Machine for producing molded fibrous pulp articles



Dec. 19, 1939.

w. H. RANDALL E1 AL ,183,8 9 MACi'IINE FOR PRODUCING MOLDED FIBROUS PULP ARTICLES Filed May 7, 1957 2 Sheets-Sheet l 6.1.

. g s 2 l {'1 x fizventom Waltar H. 12a nda, LL an. :1 Fred C. Harper Dec. 19,1939. w, RANDALL AL 2,183,869

MACHINE FOR PRODUCING MOLDED FIBROUS PULP ARTICLES Filed May 7, 1937 2 Sheets-Sheet 2 113061113115 NalteTMRLmLall and.

Fred. C. H arpe r Patented Dec. 19, 1 939 I UNITED STATES PATENT OFFICE MACHINE FOR PRODUCING MOLDED FIBROUS PULP ARTICLES Walter H. Randall and Fred 0. Harper, Waterville, Maine, assignors, by mesne assignments, to The Canal National Bank of Portland, Port- 11, Maine, a national banking association of the United States, trustee Application May 7, 1937, Serial No. 141,292 8 Claims. (01. 9256) Our present invention relates to the produccycle, both layersbeing thereafter carried by said tion of individual molded pulp articles. Its genholding die as a composite article. eral. object is to provide a commercially satis- A third, fourth and fifth holding die, each factory machine and method by means of which carrying a composite article coacts with the sevthe articles are formed, dried and smooth-fineral relatively fixed drying and finishing dies to l; ished under heat, vacuum and pressure in the progressively dry, bond and smooth finish the form of the desired commercial article. composite articles under heat, vacuum and pres- While our invention is especially adapted for sure. the production of multilayer articles it is not The sixth holding die, carrying a dried and i0 confined thereto and the principles of our infinished article, coacts with an ejector die of the I. vention apply equally to the manufacture of sinejector unit for the removal of said article from gle layer articles. For the purposes of this apsaid holding die and the subsequent ejection plication, however, we have shown and described thereof from the machine.

a machine and method for producing multilayer Previous to the step of the rotating units articles. In such machine we provide an interall holding dies are retracted to clear their matll mittently rotating holding die unit and outside ing esthe orbit of such unit we arrange two or more It is obvi s a by Pr v m l an ous independent intermittently rotating forming die reciprocating motion to all of the holding dies units, one or more relatively fixed heated drying 0n the holding die shaft we avoid the necessity :0 and finishing dies, and an intermittently rotatof pr vi in h motion o h f the mating 2. ing ejector die unit. Pulp stock tanks arranged dies on the several units outside the orbit of the beneath each forming die unit provide for the holding dies. This simplifies and reduces to the formation of independent article layers on the minimum the amount of mechanism necessary respective dies ofsaid u t to obtain coaction between the various mating With such a machine, the independently. dies.

formed article layers are transferred from the In the accompanying drawings we have shown dies of the forming die units to the dies of the a preferred form of our invention, together with holding die unit, consolidated on said holding a simple variant thereof, which is suggestive of diesv as composite articles, and pressed, dried and the many possible modifications in design for so smooth finished between said holding dies and achieving the objects indicated. Throughout the 3. the drying and finishing dies, the articles being pecification and drawings like reference numerretained on the holding dies during the drying als are employed to indicate corresponding parts, cycle and eventually being removed from the andinthe drawings:

holding dies by the ejector dies. Fig. 1 is a vertical section through the preferred All rotating die units are simultaneously embodiment of our invention, showing all interstepped and locked in their paused positions. mittently rotating units in a dwell position with All the holding dies are simultaneously projectthe holding dies coacted with mated dies of the ed towards and coact with mating dies of the ormi and eje t r units and with the several forming and ejector die units and the relatively stationary drying and finishing dies.

40 fixed series of heated drying and finishing dies Fig. 1A is a detail of a modification.

whenever the holding dies are paused in registra- Fig. 2 is a vertical elevation, partly in section, tion with said dies. through the holding unit including the heated When the die units are in paused position, one d yin n fin the s of th h ldin holding die coacts with a forming die on the first unit being retr c d. nd a ppi ycle being 5 forming unit for the transfer thereto of the artiappr x m t ly h lf C mpl d, and

cle layer which had been formed on said forming Fig. 3 is an end view showing a mechanical ardie at an earlier step in the machine cycle. rangement for the simultaneous stepping and A second holding die, on which an article layer at o t e m tent y otat ng units had previously been deposited by a die of the wn n :.o first forming unit at a preceding step in the We have indicated at I an intermittently romachine cycle, coacts with a forming die of the ting p m y forming i unit rryin a y second forming unit for superimposing such layer desired number of forming dies for the suction under vacuum and pressure upon the article formation of article layers from one grade of layer which had been formed on said first-named pulp stock contained in a stationary stock tank 5 forming die at an earlier step in the machine l and at 2 an intermittently rotating forming 5 I" die unit carrying any desired number of forming dies for the suction formation of article layers from a second grade of pulp stock contained in a stationary stock tank 2 We have indicated at 3 a holding die unit carrying any desired number of reciprocating holding or receiving dies which may be heated if desired. Each die successively removes a formed article layer from a forming die of each forming unit. Thus a two-layer article is consolidated on each holding die under vacuum and pressure as a composite article. The composite articles are carried by said holding dies through the drying and finishing stage which covers the period during which they are successively contacted with any desired number of relatively fixed heated drying and finishing dies IA, 43 and 4C, and are finally removed from the holding dies as dried and finished articles and ejected from the machine by means of an intermittently rotating ejector unit 5 carrying any desired number of ejector dies.

The intermittently rotating units I, 2, 3 and 5 are all simultaneously stepped and latched in each paused position by any convenient mechamsm.

The units I, 2 and 5 are mounted radially adjacent the orbit of the unit 3, as are the relatively fixed drying and finishing dies 4A, 4B and 4C and the dies carried by the holding unit 3 are reciprocated for coaction with the dies of the units I, 2 and 5 and the drying and finishing dies, by cam-operated or other mechanism.

Such mechanism is so timed that the holding dies are retracted immediately prior to the start of the stepping cycle, are held retracted while stepping and are closed on their respective mating dies after stepping is completed.

Conveniently, the four rotating die units I, 2, 3 and 5, may all be geared together to rotate in unison as shown in Fig. 3, wherein master gear 8 on shaft of unit 3 drives gears 6, I and 9 on shafts of units I, 2 and 5 respectively, to thereby rotate' said units. Intermediate gears ID are interposed between gears 8, I and 9 for the purpose of obtaining required direction of rotation of the units driven by gears 1 and 9 as shown by the arrows in said figure.

Step by step motion may be simultaneously imparted to the units I, 2, 3 and 5 by means of a modified Geneva drive, as shown in Fig. 3. The Geneva roll II is driven by a continuously rotating drive shaft I2. The Geneva wheel I3 is mounted on and drives shaft of unit 3 and is provided with a series of spaced slots I3, corresponding in number and spacing to the number and spacing of the holding dies.

During the period in which the Geneva II is disconnected from the Geneva wheel I3, the Geneva wheel is locked in its dwell position by means of latch pawl I 4 which is operated through suitable linkage I5 from a cam I5 fast on driveshaft I2, the wheel I3 being notched as at I3 to receive the latch pawl.

, While we have shown a Geneva drive for intermittently rotating the units I, 2, 3 and 5 simultaneously, other drive means may be employed, as for example, a cam and latch mechanism.

Any suitable mechanism may be employed for advancing and retracting the reciprocating holding dies relative to the dies of units I, 2 and 5 and the drying and finishing dies 4A, 4B and 40 in timed relation to the stepping of said units.

As here shown (see Figs. 1 and 2) we provide a cam-operated toggle for imparting this movement to the holding dies. Cam 2 is loosely mounted on the same shaft as holding unit 3, and is geared to continuously rotating gear 23. Cam 22 actuates cam arm 24 which is keyed to shaft 25 carried by holding unit 3. Also keyed to shaft 25 is segmental gear 26 which meshes with a segmental gear 21. an oscillating member 28 loosely mounted on the shaft which carries the holding unit 3 and oscillating member 28 is provided with toggle links 29, which links are connected to slide rods 30. carrying the holding dies, these slide rods being radially guided and supported in guide blocks 3I.

Referring to Fig. 1 wherein all units are shown paused in their rotation, the cam 22 has swung the cam arm 24 to a position where the toggle linkage 29 is straightened to thereby force the holding dies radially outwardly into coaction with their respective mating dies.

The position of the cam arm with relation to the cam raceway previous to the start of the stepping motion of unit 3 is approximately that shown in Fig. 2, where the holding dies have been retracted and the stepping motion of unit 3 started. As soon as the holding dies have been retracted by the cam operated mechanism the stepping of the unit starts. During the stepping period the relation between the speed of rotation of cam 22 and the stepping of unit 3 is such that the holding dies are held in the retracted or Gear 21 is carried byopen position shown in Fig. 2. As soon as the stepping motion is completed and unit 3 comes to rest, the continued rotation of cam 22 swings the cam arm to the position in the cam raceway shown in Fig. 1, thereby causing the holding dies to move out radially and coact with their respective mating dies.

The speed of rotation of cam 22 with respect to the stepping and dwell motion of the holding unit 3 is such that cam 22 rotates approximately 300 from the position shown in Fig. 1 before the rotating units begin to step. This amount of rotation of the cam 22 not only holds the holding dies in contact with their respective mating dies during a large percentage of the dwell period, but also just previous to the start of the step, the cam arm, by reason of the shape of the cam raceway, is thrown an angular amount sufficient to retract the holding dies from their respective mating dies and to give suflicient mechanical clearance so that the rotating units may step without any interference between holding dies on unit 3 and their mating dies on the other rotating or stationary units.

Means are provided to apply vacuum to the dies of the forming units for the suction formation of article layers thereon. Both vacuum and air are used on the forming units and the ejector unit for article transfer as may be required.

The holding dies are provided with connections for applying vacuum to hold the articles and/or article layers thereon during the travel of said dies and/or to remove the steam vapors given off by the drying articles, and provision is also made for sending a blast of air through each holding die when registered with an ejector die to transfer the dried and finished articles thereto.

The heated drying and finishing dies may, if desired, also be provided with connections for applying vacuum to remove the steam vapors given off by the drying articles being compressed between these dies and the holding dies.

Themachine is equipped with appropriate ports and valves for properly timing the application of vacuum and air to the various dies as required.

For convenience of reference. the dies of forming die unit I are consecutively designated from I to I; those oi forming die unit 2 from 2' to 2; those of holding die unit! from 3 to l: and those of ejector unit I from-5' to 8. All

dies or the units I, 2, 3 and I are foraminous as means conventionally it is desired to accelerthe dies of the unit 3 shown at H. However, if ate the rate ofdrying may likewise be heated.

In operation, all rotating units are simultaneously stepped and locked in their paused positions. While so locked, forming die I of unit i and forming die 2 of unit 2 are immersed in tanks I and 2 respectively, for the suction formation of article layers thereon (see Fig. 1).

All holding dies on unit 3 have been projected outwardly and are coacting with their mating dies. Holding die 3 is in pressure contact with a previously formed article layer on form die I. Holding die 3 with a previously deposited layer thereon, is in pressure contact with an independently formed article layer on forming die 2 and both layersare being consolidated as a composite article. Holding dies 3 3 and 3 with their composite articles thereon are coacted with the drying and finishing dies 4A, 4B and C respectively. Holding die 3 with a dried and finished article thereon is coacted .with ejector die 5' of the ejector unit 5 for the transfer of the dried article thereto and for subsequent ejection from the machine.

After an interval which is determined by the amount of drying time at each of the three drying stations all holding dies are retracted (see Fig. 2) and the several rotating units step one full step ahead (it being noted that in Fig. 2 the holding unit is shown as only approximately half way through a step). i 7

Holding die 3 with the article layer which was placed thereon by forming die I of unit I when at the position of Fig. l'now occupies the position formerly occupied by holding'die 3'' so that when the several rotating units again pause and the holding dies are again coacted with their mating dies, there will be placed on holding die 3 a second article layer from forming die 2 01' unit 2. The other holding dies have, of course,

likewise stepped ahead one die position. The composite articles on dies 3', progressively dried, bonded, and smooth-finished 3 and 3 are being by dies 4A, 4B and 4C, the dried and finished article on holding die 3 is being removed by ejector die and holding die 3 is having a new article layer placed on it unit I.

Any desired medium, as steam, electricity or the like may be employed for heating the drying and finishing dies and/or the holding dies, and the dwell time for each stepping cycle oi. the machine is of sufllcient duration to insure that after contact with the final drying die 40 the article is sufliciently dry for its removal from the machine.

All dies except the holding dies are preferably spring-backed as indicated at S to insure uniform pressureon the article or article layers when the dies coact.

Obviously, the machine may be equipped with a third forming unit if desired for the formation of a three-layer article. Obviously also as many adjacent sets of die units may behmounted on the shafts I, 2, 3 and 5 as desired, with corresponding increase in drying and finishing dies.

- 'In the-modification by forming die l of Mm 3 Obviously also by omitting the second forming die 2, single layer article may be manufactured by this machine. If so desired a fourth drying die may be-mounted in the position occupied by forming unit 2 thus accelerating drying when the machine is used for the manufacture of a single layer article.

It is also obvious that in its most simplified form the machine may have only one reciprocable holding die on rotating unit 3 and one forming die on forming,unit l (and one forming die on forming unit 2 if a multi-layer article is being manufactured) and one die on ejector unit I and one finishing die located as may be desired between the forming die unit (or units) and the ejector die unit I.

It is obvious that the number of dies on the holding unit may with corresponding increase in the number oi. finishing dies. of drying stations would decrease the required time for drying at any one station thus shortening the stepping cycle and increasing the rate of producing finished articles. Increasing the number of dies on the holding unit would not necessitate any increase in the number of dies on either the forming or ejector units.

While we have shown and described a series of rotating unitsdriven from a single source and stepping in unison, it is obvious that each rotating. unit might have its own independent drive and that if so driven the stepping of the' units need not necessarily be in unison so long as the required coaction between mating dies is obtained.

It is obvious that if desired the machine as above described may be so modified that two or more pulp layers may be transferred in superimposed order to each holding die from two or more forming dies of one or all of the forming units. This may be readily accomplished by rotating the forming unit or units two or more steps for each step of the holding unit and successively coacting each holding die with each of the forming dies thus stepped in registration with it for successively removing the pulp layer from each forming die and transferring them in superimposed order to the holding die. For example it might be desired to have a multilayer article of such characteristics that it would be an advantage to have it composed of two or more individual layers of pulp from forming dies of unit I only or one or more pulp layers from the forming-dies of both units l and 2.

spraying oLa pulp layer on forming dies of either of the rotating forming. die units instead of immersing said dies in a pulp stock tank as in Fig. 1. In this figure we have indicated at 2 a cylinder which is adapted to be raised and lowered in timed relation to the intermittent travel of the forming dies by any appropriate means, not shown. teriorly oi the cylinder are supplied with liquid pulp mixture under pressure from any suitable supply source. The sprays are under the control of valves (not show) adapted to be opened and closed during the period in which the cylinder is raised in contact with a forming die for the spraying of a pulp layer thereon.

Other various modifications in machine and method may obviously be resorted to within the spirit and scope of our invention as defined, by the appended claims,

We claim- Such an increase in the number of Fig. 1A we provide for.

be increased to more than six Spray nozzles N located in- 1. In a pulp molding machine for producing individually die molded and die dried fibrous pulp articles, a foraminous forming die, a drying die, andaradiallyreciprocable foraminous holding die, means for depositing a pulp layer on said forming die, means for heating said drying die, means for revolving the forming die and the holding die step by step through orbitally adjacent paths into paused coactive alinement with each other and thereafter for bringing the holding die into paused coactive alinement with the drying die, means for radially projecting the holding die in a sliding rectilinear path first towards and away from the forming die to transfer the pulp layer from the forming die to the holding die and thereafter for radially projecting the holding die in a sliding rectilinear path towards the drying die to dry the pulp layer under heat and pressure between the holding die and the drying die, and means for ejecting the dried article from the machine.

2. In a pulp molding machine for producing individually die-molded and die-dried multi-layer fibrous pulp articles, a drying die, a radially reciprocable foraminous holding die, independent forming units each having a foraminous forming die, means for depositing a pulp layer on each forming die, means for heating said drying die, means for revolving the forming dies and the holding die step by step in orbitally adjacent paths to bring the holding die successively into paused coactive alinement first with each forming die and thereafter into paused coactive alinement with the drying die, means for successively radially projecting the holding die in a sliding rectilinear path towards and away from the forming die of each forming unit to transfer the pulp layers from the forming dies in superimposed order to the holding die and thereafter for radially projecting the holding die in a sliding rectilinear path towards the drying die to dry and bond the composite article under heat and pressure between said dies, and means for ejecting the dried article from the machine.

3. In a pulp molding machine for producing individually die-molded and die-dried multi-layer fibrous pulp articles, a series of foraminous forming dies, a drying die, and a radially reciprocable foraminous holding die, means for heating said drying die, means for revolving the forming dies and the holding die step by step in orbitally adjacent paths to bring the holding die successively into paused coactive alinement first with each forming die and thereafter into paused coactive alinement with the drying die, means for depositing a pulp layer on each forming die, means for successively radially projecting the holding die in a sliding rectilinear path towards and away from said forming dies to successively transfer a desired number of pulp layers from the forming dies in superimposed order to the holding die and thereafter for radially projecting the holding die in a sliding rectilinear path towards the drying die to dry and bond the composite article under heat and pressure between said dies, and means for ejecting the dried article from the machine.

4. A fibrous pulp molding, drying and finishing machine, comprising a pair of spaced parallel intermittently revolving shafts, a foraminous forming die mounted on one shaft, a radially reciprocable foraminous holding die of complemental shape to the forming die mounted on the other shaft for timed coactionwith the forming die, a relative1y fixed dry die of complemental shape to the holding die mounted outside but adjacent to the orbit of the holding die for timed contact by said holding die, means for heating said drying die. means for revolving the holding and forming die shafts step by step to carry the I respective dies thereon through orbitally adjacent paths into paused coactive alinement with each other and thereafter in the continued stepping of the holding die shaft to bring the holding die into paused coactive alinement'with the drying 1.

die, means for locking said shafts in their paused positions, means for forming a wet article on said forming die, a single means operative while said shafts are paused for radially projecting the holding die in a sliding rectilinear path into 1 contact with and retracting it from the forming die to transfer the wet article from the forming die to the holding die and thereafter for radially projecting the holding die in a sliding rectilinear path into contact with and retracting it from m the drying die to dry and finish the article under 'heat and pressure between said holding and drying dies, and means for ejecting the dried and finished article from the machine.

5. The machine of claim 4, the means for radi- 25 ally reciprocating the holding die comprising a free-running cam on the holding die shaft, means for continuously rotating said cam in timed relation to the step by step rotation of the holding die shaft, a cam arm actuated by said cam, a

shaft carried by the holding die unit to which said cam arm is keyed, a segmental gear keyed to said last named shaft and actuated by said cam arm, an oscillating member free-mounted on the holding die shaft and having a segmental machine, comprising a pair of spaced parallel intermittently revolving shafts, two angularly spaced foraminous forming dies mounted on one shaft, a radially reciprocable foraminous holding die of complemental shape to the forming dies mounted on the other shaft for successive coaction with each forming die, a relatively fixed drying die of complemental shape to the holding die mounted outside but adjacent to the orbit of the holding die for timed contact by said holding die, means for heating said drying die, means for revolving said shafts step by step to carry the dies on the forming die shaft in an orbitally adjacent path to the die on the holding die shaft to bring the holding die successively into paused coactive alinement first with each of the forming dies and thereafter into paused coactive alinement with the drying die, means for locking said shafts in their paused positions, means for forming a wet article layer on each forming die, a single means operative while said shafts are paused for radially projecting the holding die in a sliding rectilinear path successively into contact with and retracting it from each forming 5 die to transfer the wet article layers from the forming dies in superimposed order to the holding die and thereafter for radially projecting the holding die in a sliding rectilinear path into contact with and retracting it from the drying die:

to dry, bond and finish the composite article under heat and pressure between the holding and drying dies, and means for ejecting the dried .and finished article from the machine.

7 A fibrous pulp molding, drying, and finishing ('75 .40 6. A fibrous pulp molding, drying and finishing intermittently revolving shafts adjacent and parallel to the holding die shaft, a foraminous forming die on each of said pair of shafts of complemental shape to the holding die, a relatively fixed drying die of complemental shape to the holding die mounted outside but adjacent to the orbit of the holding die for timed contact 'by the holding die, means for heating said drying die, means for revolving the holding and forming die shafts step by step to carry the dies thereon in orbitally adjacent paths to bring the holding die successively into paused coactive alinement with each forming die and thereafter into paused coactive alinement with the drying die, means for locking said shafts in their paused positions, means for forming a wet article layer on each forming die, a single means operative while said shafts are paused for radially projecting the holding die in a sliding rectilinear path successively into contact with and retracting it from each forming die to transfer the wet article layers from said forming dies in superimposed order to the holding die and thereafter for radially projecting the holding die in a sliding rectilinear path into contact with and retracting it from the drying die to dry bond and finish the composite article under heat and pressure between said holding and drying dies, and means for ejecting the dried and finished article from the machine.

8. A fibrous pulp molding, drying, and finishing machine, comprising an intermittently revolving shaft on which is mounted a series of angularly spaced radially reclprocable foraminous holding dies, a pair of spaced parallel intermittently revolving shafts adiacent and parallel to the holding die shaft, a series of angularly spaced foraminous dies of complemental shape to the holding dies on each of said pair of shafts, a series of angularly spaced relatively fixed drying dies of complemental shape to the holding dies mounted outside but adjacent to the orbit of the holding dies, means for heating said drying dies, means for revolving the holding and forming die shafts step by step to carry the dies on the forming shafts in orbitally adjacent paths to the dies on the holding die shaft to bring each holding die successively into pausedcoactlve alinement with a forming die on each forming die shaft and thereafter into paused coactive alinement with each drying e, means for locking said shafts in their paused positions, means for forming a wet article layer on each forming die, a single means operative while said shafts are paused for radially projecting each holding die in a sliding rectilinear path successively into contact with and retracting it from a forming die on each forming die shaft to transfer the wet article layers from said forming dies in superimposed order to the holding die and thereafter for successively radially projecting each holding die in a sliding rectilinear path into contact with and retracting it from each drying die to progressively dry, bond and finish the composite article under heat and pressure between said holding and drying dies, and means for ejecting the dried and finished articles from the machine.

' WALTER H. RANDALL,

FRED C. HARPER. 

